Escalator



Aug. 28, 1928. 1,682,052

A. RADCLIFFE ESCALATOR Filed Jan. 30. 1926 Patented Aug. 28, 1928.

UNITED STATES ARTHUR RAJJCLIFFE, F BOSTON, MASSACHUSETTS.

E'SCALATOR. 3

Application filed January so, 1926. Serial No. 34,929.

This. invention relates to escalators and partlcularly to those of the descending type,

and has for its object to provide the same with mechanism for controlling the operation of the same and responsive to the speed of the escalator; v

Provision is made for enabling the control mechanism to cause a slowing down of the escalator when the speed of the latter reaches a given or predetermined point, and to stop theescalator when the speed of the latter reaches a higher given or predetermined point. v e e The control mechanism may and prefer ablywill be constructed and arranged to effect a slowing down of the speed, when the latter exceeds the normal speed at which it is desired the escalator should run by 20%, and to stop the escalatorwhenthe speed exceedsthe normal by40%,as, for instance, if the escalator should runaway. p

. In thepresentinstance, the invention is embodied in an escalator-driven by an elec trio motor, and consists essentially of a governor responsive to the speed of the esca- 7 later and co-operatingiwith a plurality of circuit controllers, one of which is operated by the governorto slow down the speed of the escalator when said speed; exceeds the normal by 20%, and the other of which is operated by the governor to stop the escalator when the speed of the latter reaches the higherlimit of 40% of the normal speed. I

These. and. other features of this invention will behereinafter described and pointed out in the claims atthe end. of this specification.

Fig. 1 represents a sufiicient portion of a motor driven escalator embodying the invention to enable it to be understood;

M Fig. 2, a diagrammatic viewofthe circuits provided with the governor-operated circuit controllers, showing the latter in the positions they occupy when the escalator is running at normal speed;

Fig. 3, adetail of the governor and the circuit controllers operated thereby, showing the relation of theseparts when the speed reaches 20% increase;

Fig. 4, aview like Fig. 3, with the parts in the positions they occupy when the speed reaches the higher limit of 40%, and

Fig. 5, a detail of the housing for the governor and circuit controllers co-operating therewith and the gearing for driving the governor.

Referring to the drawing, A represents an escalator such as now in common use and only the upper portion of which is shown in Fig. 1. The escalator A is provided with an endless conveyer member, preferably a chain 10 passed about a sprocket wheel 12 on a shaft 13 supported by the framework 14, which shaft is driven by an electric motor 15 mounted upon a suitable support, repre sented by the line 16. V

The electric motor 15 is operatively con nected with the upper shaft 13 of the escalator as herein shown by a link chain 17 passed about a sprocket wheel 18 on the armature shaft 19 of the motor, and about a large sprocket wheel 20 on a countershaft 21, which-is geared to a shaft 13 by a pinion 22 and gear 23.

The countershaft 21 is geared to a governor located in a box orhousing 25 supported by the framework 14, and in the present instance one type of governor is shown in Fig. 2.

The governor may be of any suitable or known construction and is herein shown as provided with weights 27 connected by links 28, 29 to sleeves 30, 31, one of which as 30 is fixed and the other 31 is movable on a shaft 32 provided with a spring33.

The governor shaft 32 outside the housing 25 is provided with a bevel gear 35 which meshes with a'bevel gear 36 on a shaft 37 supported by a bracket 38 mounted onthe countershaft 21,, which is provided with a bevel gear 39 in mesh with a bevel gear 40 on theshaft 37. V

In the present instance, the movable sleeve 31 of the governor is provided with an arm 41 having a portion or finger 42 substantially parallel to the shaft 32 and provided with two lugs or projections 43, 44, which are separated by a substantial space and one of which as 44 is materially longer than the other, for a purpose as will be described.

The lugsv or projections 43, 44 co-operate with the movable members 45, 46 of two switches or circuit controllers, said members being represented in the diagrammatic figures as pivoted levers, which co-operate with the fixed members 48, 49 of the switches.

The lug 43 co-operates with the movable switch member to close the circuit in which said switch is included so as to maintain it closed while the speed of travel of the conveyer member 10 is normal and also as long as it does not exceed the normal speed above 20%, whereupon it is moved by the governor in response to the increased speed, out of engagement with the movable member and allows the latter to open the circuit in which it is included, as represented in Fig. 3.

When this occurs, the lug 4 1 is still in contact with the movable switch member 16 and maintains closed the circuit in which the member 16 is included, as represented in In the present instance, the switch 45, 4:8 is included in circuit with 'a solenoid 50 whose armature 51 constitutes the movable member o'f'a switch, which controls a shunt circuit for a resistance 52, which is normally in series with the field 53 of the electric motor 15.

The shunt circuit includes liXed terminals 55, 56 with which the armature 51 co-o'per'atcs, and when the escalator is'running at normal speed and up to an increase or 20%, the solenoid'50 is energized and its armature 51 opens the shuntcircuit't'or the resistance 52. \Vl en the speed of the. escalator reaches the 20% increase, the governor permits the-switch 15, 48 inthe solenoid circuit to open, thereby d'eenergizing the solenoid 50, which allows the armature 51 to close the shunt circuit and cut out the resistance 52 from the field circuit of the motor, which increases the strength of the field and slows down the motor. As the meter slows down to normal speed, the governor operates in response thereto and moves the lug 43 from the position shown in Fig. 3 into that shown in -Fig. 2.

' If the speed or the escalator should in crease to the limit of 10% above the normal, the governor moves th'econtrolling member 41, 12 into the position shown in Fig. 4, with the lug 14 out oi? engagement with the switch arm 16, which latter opens the circuit in which it is included, which circuit as herein shown includes the holding coil for the main circuit breaker or switch 61,'which is included in circult with the motor 15 and with the main lines 62, 63.

This circuit may be designated the motor circu t and includes solenoid 04 whose cores l with brake shoes 66 co-opd 1. use drum 67 on the armature shaft 19 oi: the motor.

- The brake shoes 66' are disengaged from the drum 67 as long as the motor circuit is closed, but when opened, the brakes are applied to the drum by the springs 68.

It will be observed that the lug 44 on the centrolling member -'i1-, 42 is materially longer than the lug 43, so that when the lug 13 is disengaged from the switch member 45, the lugel'l 'willremain in engagement with the switch member 16 and the motor circuit will remain closed as long as the speed or the escalator is below the maximum limit set, which is herein specified as 10% increase above the normal.

It will further be observed that when the crating speed or the escalator reaches a point at which it would be dangerous, and particularly in the case or a descending escalator, which for any reason should run away, the motor circuit is opened and the brakes are applied to stop the escalator.

The motor circuit controlled by the governor-actuated controlling member may also include in it a circuit controller 7 0, 71 (see Fig. 2), which is capable of being o'pened'by theescalator under an abnormal condition of use, as for instance in case the tension on the conveyer' member or chain 10 should be reduced to a given point, either by the elongation or the rupture of the chain. V

In the present instance, a single controlling member for the circuit controllers 45, 18, as, 49 is shown, and while this construction may be preferred, it is not desiredto limit the invention to the particular construction shown.

What I claim is:

1. An escalator having in combination an endless conveye'r member, an electric motor for driving saidco'nve'yer member, a circuit for said motor, a governor operatively con nected with said conveyer member and re sponsiv'e to the speed thereof, a resistance normally in series'with the field of said metor, electromagnetic means for shunting said resistance, a circuit independent of said motor circuit in which said electromagnetic means is located, a circuit controller for the circuit or said electromagnetic means, a second and independent circuit controller for the motor circuit, and a'controlling member co-oper'ating with said circuit controllers and o'perated'by said governor to maintain both circuit controllers closed when the conveyer memberis running at normal speed, to open the circuit controller for the electromagnetic means when the s'peedof the conveyer member exceeds the normal speed by a redetep mined amount, to maintain the independent circuit controller for the motor circuit closed at the increased speed of the ccnve'y'er member, and to open the second independent ci'r cuit controller when the speed of the conv'eyer inember'is increased a further predetermined amo'unt; I

2. An escalator having in combination an endless conveyor member, an electric motor for 'drivingfsaid conveyer member, a circuit for said motor, a governor op'er'atively connected with said conveyer member and responsive to the speed thereof, a plurality of independent circuits provided with circuit controllers, and a controlling member co-opcrating with said independent circuit controllore and operated by said governor to maintain both of said circuit controllers closed when the conveyer member is running at norm'al speed, to open the circuit governed by one or said circuit controllers when the sp'eed'ot the 'conveyer member exceeds the normal speed a predetermined amount, to maintain the circuit governed by the other circuit controller closed at said increased speed of the conveyer member, and to open the circuit of the second circuit controller when the speed of the conveyer member is increased a further predetermined amount.

3. An escalator having in combination an endless conveyer member, an electric motor for driving said conveyer member, a circuit for said motor, a governor operatively connected with said conveyer member and responsive to the speed thereof, a circuit controller governing the reduction in speed of the motor when the speed of the conveyer member exceeds the normal speed a predetermined amount, a second and independent circuit provided with a circuit controller for opening the motor circuit when the speed of the conveyer member exceeds the normal speed by a further predetermined amount, and means actuated by said governor for controlling the operations of said independent circuit controllers.

4. An escalator having in combination an endless conveyor member, an electric motor for driving said conveyer member, a circuit for said motor provided with a circuit controller, a circuit breaker governing said motor circuit, a holding coil for said circuit breaker, a circuit controller for said holding coil, an independent circuit provided with an electromagnet for operating the circuit controller in said motor circuit, a circuit controller in said independent circuit, a governor operatively connected with said conveyer member and responsive to the speed thereof,

an arm movable by said governor and provided with lugs of unequal length co-operating with the circuit controllers in said independent circuit and in the circuit of said holding coil, the lug of greater length co-operating with the circuit controller for said holding coil.

In testimony whereof, I have signed my name to this specification. V

ARTHUR RADCLIFFE. 

